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A ratio vegetation index adjusted for soil brightness / D.J. Major in International Journal of Remote Sensing IJRS, vol 11 n° 5 (May 1990)  

Public [article]  inInternational Journal of Remote Sensing IJRS > vol 11 n° 5 (May 1990) . - pp 727 - 740 Titre : A ratio vegetation index adjusted for soil brightness Type de document : Article/Communication Auteurs : D.J. Major, Auteur ; F. Baret, Auteur ; Gérard Guyot, Auteur Année de publication : 1990 Article en page(s) : pp 727 - 740 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] couleur du sol [Termes IGN] humidité du sol [Termes IGN] indice de végétation [Termes IGN] luminance lumineuse [Termes IGN] rayonnement proche infrarouge [Termes IGN] réflectance du sol Résumé : (Auteur) Improved parameters for a soil-adjusted vegetation index (SAVI) are derived using SAIL model output for simulated wheat canopy reflectance. The SAVI is much less sensitive than the ratio vegetation index to changes in background caused by soil colour or surface soil moisture content. The parameters are developed to minimize variability due to soil brightness over the practical range of solar elevations, leaf angle distributions (LAD) and leaf area indices (LAI). The parameters are added to the near-infrared (NIR) and red reflectances before calculating the NIR/red ratio. Three new versions of the SAVI are developed based on the theoretical consideration of the effects of wet and dry soils. All three are superior to the NIR/red ratio, the perpendicular vegetation index and a soil-adjusted vegetation index. Our simplest version requires the addition of a parameter to the red reflectance. The second and third versions require an iterative procedure to find the best parameters that are then added to the red or the NIR and red reflectances. In general, SAVI adjustment parameters required to remove soil-brightness effects decrease as factors that obscure the soil-surface increase. Low solar elevation and high LAI result in increasingly negative values for the parameters. The NIR/red ratio is the vegetation index least influenced by soil brightness at LAI greater than three. Our iterated versions have lowest overall errors but are occasionally subject to higher errors at the combination of low zenith angles and erectophile canopies. The SAVI based on the bare soil reflectance performs best on field data. Numéro de notice : A1990-085 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431169008955053 En ligne : https://doi.org/10.1080/01431169008955053 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=25502 [article]

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080-90051	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Crop biomass evaluation using radiometric measurements / F. Baret in Photogrammetria, vol 43 n° 5 (June 1989)

Public [article]  inPhotogrammetria > vol 43 n° 5 (June 1989) . - pp 241 - 256 Titre : Crop biomass evaluation using radiometric measurements Type de document : Article/Communication Auteurs : F. Baret, Auteur ; D.J. Major, Auteur ; Gérard Guyot, Auteur Année de publication : 1989 Article en page(s) : pp 241 - 256 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] absorption [Termes IGN] cultures [Termes IGN] indice de végétation [Termes IGN] masse végétale [Termes IGN] valeur radiométrique Numéro de notice : A1989-182 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=25142 [article]

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Code-barres	Cote	Support	Localisation	Section	Disponibilité
081-89021	RAB	Revue	Centre de documentation	En réserve L003	Disponible